Support multiple clusterqueues / localqueues with xpk

[Obliviour]

xpk currently supports one cluster queue / local queue. If an xpk cluster administrator wants to split capacity between different use cases, they would currently have to create separate xpk clusters.

xpk can support multiple quotas within the same cluster by using multiple clusterqueues / localqueues.

# create a cluster that organizes resource usage limits across different queues 
xpk cluster create --quotas= {local_queue_name: device_type, num_slices, local_queue_name2: device_type, num_slices}
# xpk needs to check that the quotas are less than or equal to the quota available
# resources not specified with a quota will be sent to the default cluster kueue
# run a workload against one of the above queues (local queue name)
xpk cluster create --queue=local_queue_name
# by default the queue will be multislice-queue
# if queue doesn't exist, xpk can list the queues available in the error.

[bernardhan33]

+1. One issue here also is that the local queue is a namespaced object and currently is only created under the default namespace.

As we are aware that it is generally recommended not to run applications in the default namespace, are there considerations of improving this behavior?